Assessment of the Impact of Salt Iodisation Programmes on Urinary Iodine Concentrations and Goitre Rates: A Systematic Review

Abstract

Introduction. Two main strategies are currently recommended for the prevention and control of iodine deficiency in the world: implementation of universal salt iodisation programmes and permanent monitoring of iodine consumption by the population. Although iodine intake and coverage iodised salt have increased in the world population, iodine deficiency disorders (IDDs) may still be a public health problem in a few countries or communities. Objective. To assess the impact of salt iodisation programmes on urinary iodine concentrations and goitre rates in the world population. Methodology. A systematic review based on the PRISMA method. We obtained articles from Scopus, Science Direct, MEDLINE databases, and other sources between March and April 2020, without limitation of dates. “Iodisation” AND “urinary iodine concentrations” AND “goitre” in English, Portuguese, and Spanish without filters and clinical trial, case-control, and cross-sectional studies were included in this review. Results. Of 479 abstracts, twenty-three were eligible. Coverage on iodised salt was in the range of 16 to 98%, and 11 studies had been sufficient, whilst eight studies had adequate iodine concentration in salt and three excess. 81.8% of studies that had an adequate median of UIC had a good impact in their respective salt iodisation programmes. Conclusion. After 18 years of salt iodisation programme implementation in the 13 countries, the majority achieved sustaining elimination of IDD whilst all had adequate median UIC; however, more detailed studies are still needed to confirm that all communities are equally protected of IDD.

Estado nutricional de iodo entre gestantes usuárias da rede pública de saúde do município de Ribeirão Preto, São Paulo

“…Converging with Machamba (2021) and diverging from Macedo [33] we observed that use industrialized seasoning weekly was a predictor of iodine insufficiency regarding to a rare consumption, probably due to the low iodine content compared to salt in its pure form (43 µg/5g of seasoning versus 157 µg/5g of salt). It suggests that iodized salt in manufacturing of processed foods is compromised.…”

“…In our study, a low consumption of salt in its pure form was observed (20.3%) while there was a high consumption of industrialized seasonings (74.3%). According to Machamba (2021), seasonings were associated to lower UIC. Macedo [33] observed that industrialized seasonings were protective factors while homemade seasonings, risk factors for lower UIC.…”

“…A concentração de iodo da água tem um grande impacto sobre o status de iodo (FAN et al, 2022). Machamba (2021) verificou que, apesar do teor de iodo na água de consumo ser muito baixo, contribuiu para uma melhora nos níveis de CIU entre gestantes e lactantes.…”

“…Mioto et al[23] detected 52.2% and 4.4% of UIC below 150 μg/L and above 250 μg/L, respectively, in 273 pregnant women from São Paulo (median UIC: 146 μg/L). Saraiva et al[4] concluded that 48.7% of pregnant women in the first trimester from Rio de Janeiro, a coastal city of Brazil, showed insufficient and 4.5%, excessive UIC (median UIC: 221 μg/L) Machamba (2021). found 22.3% of iodine insufficiency and 8.2% of excessive iodine nutrition in 184 pregnant women from Viçosa (median UIC: 244 μg/L).…”